Question

A close, long term association between two or more organisms is known as

• A. Commensalism
• B. Mutualism
• C. Parasitism
• D. Symbiosis

Answer 1

The correct option is D Symbiosis

Symbiosis is any relationship between two or more biological species. Such relationships are usually long term and have a strong impact on the fitness of one or both organisms. Symbiotic relationships are categorized by the benefits. Mutualism is a relationship in which both species benefit, is common in nature. In microbiology, there are many examples of mutualistic bacteria in the gut that aid digestion in both humans and animals.

Commensalism is a relationship between species in which one benefits and the other is unaffected. Humans are host to a variety of commensal bacteria in their bodies that do not harm them but rely on them for survival (e.g. bacteria that consume dead skin). In parasitic relationships, one species benefits and the other suffers. Most of the microorganisms studied in medical microbiology are parasitic and feed on human tissue. For example, cholera, leishmaniasis, and Giardia are all parasitic microbes.